US7826392B2 - Advertisement search agent - Google Patents

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US7826392B2
US7826392B2 US11/705,105 US70510507A US7826392B2 US 7826392 B2 US7826392 B2 US 7826392B2 US 70510507 A US70510507 A US 70510507A US 7826392 B2 US7826392 B2 US 7826392B2
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message
node
advertisement
delivery
service
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US20070206596A1 (en
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Yuichi Ishikawa
Akira Tsukamoto
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NEC Corp
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NEC Corp
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00—Network arrangements or protocols for supporting network services or applications
    • H04L67/50—Network services
    • H04L67/535—Tracking the activity of the user
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/02—Details
    • H04L12/16—Arrangements for providing special services to substations
    • H04L12/18—Arrangements for providing special services to substations for broadcast or conference, e.g. multicast
    • H04L12/1863—Arrangements for providing special services to substations for broadcast or conference, e.g. multicast comprising mechanisms for improved reliability, e.g. status reports

Definitions

  • broadcast and multicast technologies have been used as means for discovering services provided on networks.
  • Nodes which provide services (hereinafter referred to as service providing nodes) on a network advertise the existence of services using broadcast or multicast to simultaneously inform nodes using all services that exist oh the same network (hereinafter referred to as service using nodes) of the existence of the services.
  • the service using nodes can simultaneously recognize all the services that exist on the network by searching for the existence of the services using broadcast or multicast.
  • Applications for discovering services based on broadcast or multicast include UPnP DA (Universal Plug and Play Device Architecture) and messenger software known as IP Messenger, which are widely used in the art.
  • the above applications are implemented to restrict the frequency of broadcast and multicast services.
  • a service providing node or a service using node to broadcast or multicast a message for advertising or searching for the service when the node machine is activated, i.e., when the application is activated, and thereafter to provide a broadcast or multicast service automatically at certain time intervals.
  • the time intervals for providing the broadcast or multicast service differ depending on how individual applications are implemented, they are generally 30 minutes each for UPnP DA, for example.
  • service using node A when service using node A is connected to a network to which service providing nodes X, Y have already been connected, service using node A has to wait until service providing nodes X, Y broadcast or multicast their advertisement messages or service using node A broadcasts or multicasts its search message, in order to recognize the existence of service providing nodes X, Y on the network.
  • service providing node when a service providing node is connected to a network and also when a node is disconnected from a network.
  • the virtual network is advantageous as described above, it also suffers the problem described above, i.e., a service providing node or a service using node, immediately after it is newly connected to a virtual network, is unable to use services on the virtual network or provide services to nodes on the virtual network.
  • the device proxy is provided in each subnet.
  • Device proxies that are present in different subnets are linked to inform service using nodes that are present in different subjects of the existence of a service immediately when required. Specifically, the following procedure is carried out:
  • the device proxy When a device proxy receives a connection request from another device proxy, the device proxy broadcasts a search message to the subject to which it is connected, for searching for a service providing node. When the device proxy receives a response frame in response to the search message, the device proxy converts the response frame into an advertisement frame, and delivers the advertisement frame to the device proxy which has sent the connection request. In this manner, a service using node can discover a service provided on the network immediately after the connection request.
  • the first drawback is that when a service providing node is connected to a network, it cannot immediately inform service using nodes already connected to the network of the information of services that are newly connected to the network.
  • a service using node when a service using node is connected to a network, a service providing node that has already been connected to the network informs the service using node of the existence of services provided by the service providing node, and when a service providing node is connected to the network, the service providing node does not advertise services provided by the service providing node to existing service using nodes.
  • the second drawback is that since a device proxy informs a newly connected node of the information of all services that exist in a subnet domain to which the device proxy is connected, the device proxy is unable to selectively advertise the existence of a service among the services that exist in the subnet domain to which the device proxy is connected.
  • a device proxy is connected to physical subnet A and virtual subnet B, and of services X, Y, Z connected to subnet A, only service X is connected to virtual subnet B.
  • node I newly connected to virtual subnet B is informed of not only service X that is connected to virtual subnet B, but also services Y, Z.
  • the third drawback is that the disconnection of a node from a network cannot immediately be indicated because a conventional device proxy does not have a function to indicate the disconnection of a node from a network. For example, when a service providing node is disconnected from a network, a service using node connected to the network is unable to detect the unavailability of the service provided by the service providing node immediately after the service providing node is disconnected. Furthermore, when a service using node is disconnected from a network, the service using node is unable to detect the unavailability of the services provided by the network immediately after the service using node is disconnected.
  • a message delivery unit delivers the search message and the service availability advertisement message which are extracted to the domain to which the node is connected. If only the search message and the service availability advertisement message delivered from the node connected to the domain, then the message delivery unit delivers the search message and the service availability advertisement message which are extracted to the node connected to the domain.
  • a node newly connected to a domain is a service providing node for providing a service to the domain
  • the node can detect the service at the domain immediately after the node is connected
  • a node newly connected to a domain is a service using node for using a service
  • the node can detect the service available at the domain immediately after the node is connected.
  • FIG. 1 is a block diagram of an advertisement search agent module according to a first embodiment of the present invention
  • FIG. 3 is a diagram showing a connected configuration in which the advertisement search agent module shown in FIG. 1 is disposed in a VPN gateway;
  • FIG. 4 is a diagram showing details of data stored in a message database (DB) of the advertisement search agent module shown in FIG. 1 which is located in the position shown in FIG. 3 ;
  • DB message database
  • FIG. 6 is a flowchart of a process of extracting a message using a third extracting function in a delivery message extractor of the advertisement search agent module shown in FIG. 1 ;
  • FIG. 7 is a block diagram of an advertisement search agent module according to a second embodiment of the present invention.
  • FIG. 8 is a flowchart of a process of generating a message in a delivery message generator shown in FIG. 7 ;
  • FIG. 9 is a flowchart of a process of extracting a message in a delivery message extractor shown in FIG. 7 when it is guaranteed that both a service availability advertisement message and a service unavailability advertisement message of all service providing nodes connected to either monitoring domain immediately before a node connection or disconnection occurs, are stored in a message DB;
  • FIG. 10 is a flowchart of a process of extracting a message in the delivery message extractor shown in FIG. 7 when it is not guaranteed that both a service availability advertisement message and a service unavailability advertisement message of all service providing nodes connected to either monitoring domain immediately before a node connection or disconnection occurs, are stored in a message DB.
  • FIG. 1 shows advertisement search agent module 100 according to a first embodiment of the present invention, which is connected to a plurality of domains 210 - 1 through 210 - m.
  • Domains 210 - 1 through 210 - m are networks which provide broadcast or multicast domains that are independent of each other. A broadcast or multicast message delivered from a domain does not reach another domain. Examples of domains include a physical subnet (LAN), a virtual LAN (a VPN in layer 2 level) constructed by VLAN, Softether, or the like, a corporate intranet, an application-level virtual network constructed by a P2P file sharing application or the like such as Gnutella or the like.
  • LAN physical subnet
  • VPN virtual LAN
  • Softether a VPN in layer 2 level
  • a corporate intranet an application-level virtual network constructed by a P2P file sharing application or the like such as Gnutella or the like.
  • Nodes 211 - 11 through 211 - mn are nodes connected respectively to domains 210 - 1 through 210 - m and running an application for advertising and searching for services using broadcast or multicast techniques.
  • the application run on nodes 211 - 11 through 211 - mn may be UPnP DA, IP Messenger, Gnutella, or the like, for example.
  • Each of nodes 211 - 11 through 211 - mn may be connected to a plurality of domains 210 - 1 through 210 - m.
  • Nodes 211 - 11 through 211 - mn are classified into one or both of service providing nodes which provide services and service using nodes which use services.
  • a node having a Control Point function serves as a service providing node
  • a node having a Nedia Server function serves as a service using node.
  • a node both provides and uses services.
  • Nodes 211 - 11 through 211 - mn may be not only ordinary PC terminals, but also terminals other than PCs such as DVD recorders, printers, home routers, etc. insofar as they run an application for advertising and searching for services using broadcast or multicast techniques.
  • terminals other than PCs such as DVD recorders, printers, home routers, etc. insofar as they run an application for advertising and searching for services using broadcast or multicast techniques.
  • television sets, DVD recorders, and small-size stereo systems may be used as nodes 211 - 11 through 211 - mn operable under UPnP AV Architecture.
  • Services are searched for when service using nodes broadcast or multicast a search message through connected domains 210 - 1 through 210 - m .
  • the search message corresponds to a Discover message prescribed by SSDP for UPnP DA.
  • the service availability advertisement message, the service unavailability advertisement message, and the search message will hereinafter collectively be referred to as an advertisement search message.
  • Advertisement search agent module 100 acquires advertisement search messages delivered from nodes 211 - 11 through 211 - mn of domains 210 - 1 through 210 - m .
  • advertisement search agent module 100 delivers the acquired messages to domains 210 - 1 through 210 - m to which the nodes are connected, so that nodes 211 - 11 through 211 - mn can detect the services provided at connected domains 210 - 1 through 210 - m immediately after nodes 211 - 11 through 211 - mn are connected.
  • advertisement search agent module 100 delivers the acquired messages to domains 210 - 1 through 210 - m to which the nodes are connected, so that the nodes already connected to domains 210 - 1 through 210 - m can immediately detect the services provided by nodes 211 - 11 through 211 - mn .
  • advertisement search agent module 100 delivers the acquired messages to domains 210 - 1 through 210 - m from which the nodes are disconnected, so that nodes 211 - 11 through 211 - mn can detect the unavailability of the services provided at domains 210 - 1 through 210 - m immediately after nodes 211 - 11 through 211 - mn are disconnected.
  • advertisement search agent module 100 delivers the acquired messages to domains 210 - 1 through 210 - m from which the nodes are disconnected, so that nodes 211 - 11 through 211 - mn already connected to domains 210 - 1 through 210 - m can detect the unavailability of the services provided by nodes 211 - 11 through 211 - mn immediately after nodes 211 - 11 through 211 - mn are disconnected.
  • Advertisement search agent module 100 acquires advertisement search messages delivered by nodes 211 - 11 through 211 - mn in domains 210 - 1 through 210 - m . When a node is newly connected to any of domains 210 - 1 through 210 - m , if the newly connected node is a service using node, then advertisement search agent module 100 allows the newly connected node to discover the services provided by the domains to which the node is connected immediately after the node is connected.
  • advertisement search agent module 100 allows the service using nodes already connected to the domains to which the node is connected to discover the services provided by the newly connected node immediately after the node is connected.
  • advertisement search agent module 100 allows the disconnected node to detect the unavailability of the services provided at the domains from which the node is disconnected immediately after the node is disconnected.
  • advertisement search agent module 100 When a node is disconnected from any of domains 210 - 1 through 210 - m , if the disconnected node is a service providing node, then advertisement search agent module 100 allows the service using nodes already connected to the domains from which the node is disconnected to detect the unavailability of the services provided by the disconnected node immediately after the node is disconnected. To allow the node to discover available or unavailable services, advertisement search agent module 100 delivers the acquired advertisement search messages to the domains to which the node or nodes are connected.
  • Advertisement search agent module 100 is disposed in a position capable of receiving broadcast or multicast messages from domains 210 - 1 through 210 - m and of delivering broadcast or multicast messages to domains 210 - 1 through 210 - m .
  • Domains 210 - 1 through 210 - m to and from which advertisement search agent module 100 can receive and send broadcast or multicast messages will hereinafter be referred to as monitoring domains of advertisement search agent module 100 .
  • advertisement search agent module 100 shown in FIG. 1 is disposed in VLAN switch 230 which accommodates a plurality of VLANs 240 - 1 through 240 - 3 .
  • Advertisement search agent module 100 can send and receive broadcast and multicast messages to and from VLANs 240 - 1 through 240 - 3 .
  • VLANs 240 - 1 through 240 - 3 serve as monitoring domains of advertisement search agent module 100 .
  • advertisement search agent module 100 shown in FIG. 1 is disposed in VPN gateway 300 - 1 .
  • Advertisement search agent module 100 can send and receive broadcast and multicast messages to and from LAN 320 of corporation X and VPNs 310 - 1 , 310 - 2 .
  • LAN 320 of corporation X and VPNs 310 - 1 , 310 - 2 serve as monitoring domains of advertisement search agent module 100 .
  • advertisement search agent module 100 Internal details of advertisement search agent module 100 shown in FIG. 1 will be described below.
  • advertisement search agent module 100 comprises advertisement search message acquisition unit 110 , message DB 120 , node connection monitoring unit 130 , delivery message extractor 140 , and message delivery unit 150 .
  • Advertisement search message acquisition unit 110 acquires service advertisement messages and service search messages broadcast or multicast by all monitoring domains 210 - 1 through 210 - m , and stores the acquired messages in message DB 120 . If message DB 120 have already stored messages identical to the acquired messages, i.e., messages whose contents are identical to those delivered from nodes 211 - 1 through 211 - mn , then advertisement search message acquisition unit 110 may discard the acquired messages.
  • broadcast or multicast messages are messages that are broadcast or multicast in an application level such as file search messages of the P2P file sharing software, for example, then the acquisition of the broadcast or multicast messages is made possible by advertisement search message acquisition unit 110 which has at least a function to receive broadcast or multicast messages of the corresponding application.
  • advertisement search message acquisition unit 110 which reads a file from a TUN/TAP device that is bridge-connected to network interfaces connected to monitoring domains 210 - 1 through 210 - m.
  • Messages broadcast or multicast in a network level can also be acquired by monitoring, with PCAP, network interfaces connected to monitoring domains 210 - 1 through 210 - m , using a PCAP library which is capable of capturing messages that have reached the network interfaces to be monitored.
  • Message DB 120 stores messages acquired by advertisement search message acquisition unit 110 as a database. Message DB 120 accumulates therein advertisement messages and search messages of all nodes 211 - 11 through 211 - mn connected to monitoring domains 210 - 1 through 210 - m of advertisement search message acquisition unit 110 .
  • message DB 120 shown in FIG. 1 records therein the monitoring domains of advertisement search message acquisition unit 110 and the messages of service using nodes and service providing nodes which are connected to the monitoring domains, in association with each other. Specifically, message DB 120 stores therein the messages of service using nodes and service providing nodes which are connected to LAN 320 of corporation X and VPNs 310 - 1 , 310 - 2 as the monitoring domains of advertisement search message acquisition unit 110 . If advertisement search message acquisition unit 110 acquires messages using the TUN/TAP device or the like, then the header information in layer 2 level of messages is also stored in message DB 120 .
  • VPN gateway 300 - 1 can refer to broadcast or multicast messages through not only LAN 320 of corporation X and VPNs 310 - 1 , 310 - 2 , which serve as its own monitoring domains, but also LAN 330 of corporation Y that serves as a monitoring domain of VPN gateway 300 - 2 .
  • connection of a node to a monitoring domain and the disconnection of a node from a monitoring domain may be detected as follows: If a domain connection terminal is managed by a particular management server, then node connection monitoring unit 130 can monitor the connection of a node by being notified of a change in the domain connection terminal from the management server. If advertisement search agent module 100 is disposed in VLAN switch 230 or VPN gateways 300 - 1 through 300 - 2 , then node connection monitoring unit 130 can monitor the connection of a node by monitoring a setting change of VLAN switch 230 or VPN gateways 300 - 1 through 300 - 2 .
  • Delivery message extractor 140 is instructed by message delivery unit 150 to extract a message to be delivered by message delivery unit 150 , and transfers the extracted message to message delivery unit 150 .
  • Delivery message extractor 140 extracts only a message of a node related to a connected domain or a disconnected domain from message DB 120 , thereby preventing a message of a node not related to the connected domain or the disconnected domain from being delivered to the domain.
  • delivery message extractor 140 has first and second extracting functions, to be described below, and extracts a message to be delivered by message delivery unit 150 using at least one of the first and second extracting functions.
  • delivery message extractor 140 transfers a message to message delivery unit 150
  • delivery message extractor 140 informs message delivery unit 150 of the extracting function that is used to extract the message.
  • the first extracting function is a function for delivery message extractor 140 to extract, from message DB 120 , a search message or an advertisement message broadcast or multicast to the connected or disconnected node in any monitoring domain in the past, as a message to be transmitted by message delivery unit 150 .
  • the second extracting function is a function for delivery message extractor 140 to extract, from message DB 120 , a message broadcast or multicast in any monitoring domain in the past by a node connected to the monitoring domain before a node is connected thereto or disconnected therefrom, as a message to be transmitted by message delivery unit 150 .
  • Delivery message extractor 140 is initially required to recognize a node connected to a domain to which a node is newly connected or from which a node is newly disconnected. Specifically, if advertisement search agent module 100 is disposed in a VLAN switch or a VPN gateway and each domain is constructed as a virtual domain, e.g., a MAC address base VLAN or a layer 2 level VPN, then the identifier such as a MAC address or the like of a node connected to a domain in question (VLAN or layer 2 level VPN) can be recognized by confirming settings of the VLAN switch or the VPN gateway. If a domain is constructed as a virtual LAN by Softether, then the identifier (MAC address) of a node connected to a domain in question (virtual LAN) can be recognized by checking with a server which manages the virtual LAN.
  • a virtual domain e.g., a MAC address base VLAN or a layer 2 level VPN
  • advertisement search agent module 100 is positioned as shown FIG. 3 and the messages shown in FIG. 4 are stored in message DB 120 , then when terminal E is connected to VPN 310 - 2 , delivery message extractor 140 recognizes nodes connected to a domain as domains C, D, G, H. Then, delivery message extractor 140 extracts the messages Nos. 4 , 5 , 6 , 8 , 9 , 10 shown in FIG. 4 as messages to be transmitted to these nodes by message delivery unit 150 , from message DB 120 .
  • delivery message extractor 140 After delivery message extractor 140 has extracted messages using at least one of the first and second extracting functions, delivery message extractor 140 transfers the extracted messages directly to message delivery unit 150 . Delivery message extractor 140 also selects a message from the extracted messages according to a third extracting function, to be described below, and transfers the selected message to message delivery unit 150 .
  • the third extracting function is a function for delivery message extractor 140 to select a message from the messages extracted by the first and second extracting functions, in view of whether a node is connected or disconnected and the type of a connected or disconnected node, i.e., whether a connected or disconnected node is a service providing node or a service using node.
  • a process of extracting a message using the third extracting function of delivery message extractor 140 of advertisement search agent module 100 shown in FIG. 1 will be described below with reference to FIG. 6 .
  • step 1 it is determined in step 1 whether a node is connected or disconnected. If it is judged that a node is connected, then it is determined in step S 2 whether the connected node is a service using node or a service providing node.
  • a search message is selected from the messages extracted using the second extracting function in step 5 and a service availability advertisement message is selected from the messages extracted using the first extracting function in step 6 .
  • no message is selected from the messages extracted using the first extracting function and a service unavailability advertisement message is selected from the messages extracted using the second extracting function in step 8 .
  • a service unavailability advertisement message is selected from the messages extracted using the first extracting function in step 9 , and no message is selected from the messages extracted using the second extracting function.
  • a connected or disconnected node is a service providing node or a service using node by referring to the messages stored in message DB 120 for example.
  • Nodes with only search messages stored in message DB 120 can be judged as service using nodes.
  • Nodes with at least one of service availability messages and service unavailability messages stored in message DB 120 can be judged as service providing nodes.
  • nodes A, C, E, G, and I are service using nodes
  • nodes B, D, H, and J are service providing nodes.
  • delivery message extractor 140 may select a message simply in view of whether a node is connected or disconnected, without regard to the type of a connected or disconnected node. In this case, step 2 and step 7 shown in FIG. 6 are skipped, and if it is judged in step 1 that a node is connected, the messages shown in steps 3 through 6 are selected. If it is judged in step 1 that a node is disconnected, the messages shown in steps 8 , 9 are selected.
  • Message delivery unit 150 will be described below.
  • message delivery unit 150 When message delivery unit 150 is notified of the connection or disconnection of a node from node connection monitoring unit 130 , message delivery unit 150 instructs delivery message extractor 140 to extract a message and delivers the message transferred from delivery message extractor 140 .
  • Message delivery unit 150 delivers the message transferred from delivery message extractor 140 to only the connected or disconnected node or the domain to or from which the node is connected or disconnected, thereby preventing messages transmitted in the domain to or from which the node is connected or disconnected, from being delivered to nodes unrelated to the domain.
  • Message delivery unit 150 has at least one of a first delivery function (c) and a second delivery function (d) described below, and delivers a message using the function.
  • Message delivery unit 150 delivers a message to a domain to or from which a node is connected or disconnected.
  • message delivery unit 150 delivers the message directly without changing the header information in layer 2 level of the acquired broadcast or multicast message.
  • the message is delivered from advertisement search message acquisition unit 110 , its transmission source MAC address is delivered as the transmission source MAC address of the service using node or the service providing node which has broadcast or multicast the message.
  • message delivery unit 150 converts messages extracted using the second extracting function, of the messages transferred from delivery message extractor 140 , into unicast messages, and delivers the unicast messages to a connected or disconnected node.
  • messages that are converted into unicast messages include the following three messages (e) through (g):
  • message delivery unit 150 converts the destination MAC address of the acquired broadcast or multicast message (the header information in layer 2 level) into a connected or disconnected MAC address, and delivers the message.
  • the destination MAC address is a broadcast or multicast address.
  • Message delivery unit 150 does not convert a message extracted using the first extracting function, which does not satisfy the condition of not changing the destination MAC address and the header information in other layers, and broadcasts or multicasts the message transferred to a domain to which a node is connected or a domain from which a node is disconnected.
  • message delivery unit 150 When a message extracted using the first extracting function is transferred from message extractor 140 to message delivery unit 150 , message delivery unit 150 broadcasts or multicasts the transferred message to a domain to which the node is newly connected. At this time, the message selected in at least one of step 4 and step 6 shown in FIG. 6 is transferred to message delivery unit 150 .
  • a search message of the newly connected node is received by all nodes already connected to the domain to which the node is newly connected.
  • a response message in response to the search message is transmitted from a service providing node already connected to the domain to which the node is connected to the newly connected node. Therefore, a newly connected service using node can discover services available in the domain to which the node is connected immediately after the node is connected.
  • a service availability advertisement message of the newly connected node is sent to all nodes already connected to the domain to which the node is newly connected. Because of the service availability advertisement message sent, a service using node already connected to the domain to which the node is connected can detect services provided by the newly connected node immediately after the newly connected node is connected to the domain.
  • message delivery unit 150 converts the transferred message into a unicast message and transmits the unicast message to the newly connected node. At this time, the message selected in at least one of step 3 and step 5 shown in FIG. 6 is transferred to message delivery unit 150 .
  • the newly connected node receives a service availability advertisement message of the node already connected to the domain to which the node is connected, and can detect a service available in the domain to which the node is connected immediately after the node is connected.
  • the newly connected node receives a search message of a service using node already connected to the domain to which the node is connected.
  • a response message in response to the search message received by the newly connected node is transmitted, allowing the already connected node to detect a service provided by the newly connected node.
  • message delivery unit 150 When a message extracted using the first extracting function is transferred from message extractor 140 to message delivery unit 150 , message delivery unit 150 broadcasts or multicasts the transferred message to a domain from which the node is disconnected. At this time, the message selected in step 9 shown in FIG. 6 is transferred to message delivery unit 150 .
  • a service using node connected to the domain from which the node is disconnected receives a service unavailability advertisement message which has been broadcast or multicast, and hence is capable of knowing that a service provided by the disconnected node has become unavailable immediately after the node is disconnected.
  • message delivery unit 150 converts the transferred message into a unicast message and transmits the unicast message to the disconnected node. At this time, the message selected in step 8 shown in FIG. 6 is transferred to message delivery unit 150 .
  • the disconnected node since the disconnected node receives a service unavailability advertisement message, it is capable of knowing that a service provided in the domain from which the node is disconnected has become unavailable immediately after the node is disconnected.
  • messages may be extracted using both the first extracting function and the second extracting function, making it possible to handle the situation when either a service providing node or a service using node is disconnected. At this time, messages are extracted in both step 8 and step.
  • Advertisement search agent module 100 offers the following advantages:
  • Advertisement search agent module 100 has node connection monitoring unit 130 for detecting when a service providing node and a service using node are connected to a monitoring domain and disconnected from a monitoring domain, and recognizing the domain to or from which the node is connected or disconnected and the identifier of the node, delivery message extractor 140 for extracting either one or both of a message broadcast or multicast in the past by the node, and a message broadcast or multicast in the past by another node connected to the domain to or from which the node is connected or disconnected, based on the identifier of the node and the domain to or from which the node is connected or disconnected as recognized by node connection monitoring unit 130 , and message delivery unit 150 for broadcasting or multicasting a message extracted by delivery message extractor 140 to the domain to or from which the node is connected or disconnected if the message is a message transmitted by the connected or disconnected node, and transmitting a message extracted by delivery message extractor 140 to the connected or disconnected node if the message is a message delivered by another node connected to
  • node connection monitoring unit 130 detects the connection and recognizes the node identifier of the service providing node and the domain to which the node is connected.
  • Delivery message extractor 140 extracts at least one of (A) a service availability advertisement message broadcast or multicast in the past by the service providing node and (B) a search message broadcast or multicast in the past by another node connected to the domain to which the node is connected. If the message extracted by delivery message extractor 140 is the message (A), then message delivery unit 150 broadcasts or multicasts the extracted message to the domain to which the service providing node is connected. If the message extracted by delivery message extractor 140 is the message (B), then message delivery unit 150 broadcasts or multicasts the extracted message to the service providing node.
  • delivery message extractor 140 and message delivery unit 150 either (i) extracts only a message of a node connected to a domain to or from which the node is connected or disconnected, and delivers the extracted message only to the connected or disconnected node, or (ii) extracts only a message of the connected or disconnected node, and delivers the extracted message to the domain to or from which the node is connected or disconnected.
  • the message of the domain to or from which the node is connected or disconnected is prevented from being delivered to nodes unrelated to the domain, and the message of the connected or disconnected node is prevented from being delivered to nodes unrelated to the domain to or from which the node is connected or disconnected.
  • the newly connected service using node can discover only a service providing node connected to the domain.
  • a service providing node is newly connected to a domain
  • only a service using node connected to the domain can discover a service provided by the newly connected service providing node.
  • delivery message extractor 140 extracts a service unavailability advertisement message delivered in the monitoring domain in the past by the disconnected node or a service unavailability advertisement message delivered in the monitoring domain in the past by a node connected to the domain from which the node is disconnected.
  • Message delivery unit 150 broadcasts or multicasts the extracted message to the domain from which the node is disconnected, or transmits the extracted message to the disconnected node.
  • a node is disconnected from a domain
  • a service using node connected to the domain from which the node is disconnected is immediately able to recognize that the service provided by the disconnected node has become unavailable.
  • the disconnected node is immediately able to recognize the service provided by the domain from which the node is disconnected.
  • advertisement search agent module 100 suffers the following problems:
  • the first problem is that when a node is connected or disconnected, a service may not immediately be discovered or its unavailability may not immediately be detected depending on how messages are stored in message DB 120 .
  • advertisement search agent module 100 is only capable of delivering messages that are stored in message DB 120 at the time a node is connected or disconnected. Therefore, when a service providing node is newly connected to a domain, if a service availability advertisement message of the service providing node or a service search message of a node connected to the domain to which the service providing node is connected is not registered in advance in message DB 120 , then the node connected to the domain to which the service providing node is connected cannot immediately discover a service provided by the newly connected service providing node.
  • advertisement search agent module 100 delivers a search message to immediately discover a service (if the connected node is a service providing node, advertisement search agent module 100 transmits a search message delivered in the past by a node already connected to the domain to which the node is connected, and if the connected node is a service using node, advertisement search agent module 100 broadcasts or multicasts a search message delivered in the past by the connected node to the domain to which the node is connected), but advertisement search agent module 100 may not be able to discover a service by delivering the search message depending on how an application is installed on the node.
  • a service providing node transmits a response message in response to the search message received from advertisement search agent module 100 to a service using node. If an application on the service using node is installed in a manner to be able to receive a response message at all times, then the service using node can discover a service when it receives a response message. However, if an application on the service using node is installed in a manner to be able to receive a response message only for a certain time after the service using node has transmitted a search message, then the service using node discards a received response message after elapse of the certain time. In this case, the service using node fails to discover a service.
  • the advertisement search agent module according to the second embodiment can deliver not only messages actually delivered from nodes in the past, but also messages generated by the advertisement search agent module itself.
  • advertisement search agent module 102 does not have advertisement search message acquisition unit 110 for acquiring messages broadcast or multicast by nodes connected to monitoring domains, but delivery message generator 160 for generating a service availability advertisement message and a service unavailability advertisement message. Furthermore, advertisement search agent module 102 has delivery message extractor 141 whose function is different from the function of delivery message extractor 140 according to the first embodiment.
  • Delivery message extractor 141 and delivery message generator 160 of advertisement search agent module 102 shown in FIG. 7 will be described below.
  • Other components of advertisement search agent module 102 are identical to those according to the first embodiment, and will not be described in detail below.
  • Delivery message extractor 141 has a function to instruct delivery message generator 160 to generate a message, in addition to the function of delivery message extractor 140 according to the first embodiment.
  • Delivery message extractor 141 also has at least one of a first message generation instructing function to specify a domain to which a node is connected or a domain from which a node is disconnected as a domain for which a message is to be generated and to instruct delivery message generator 160 to generate a message for the domain for which a message is to be generated, and a second message generation instructing function to specify a connected or disconnected node as a node for which a message is to be generated and to instruct delivery message generator 160 to generate a message for the node.
  • Instructions given from delivery message extractor 141 to delivery message generator 160 include a node or a domain for which a message is to be generated, and the type of a message to be generated, i.e. whether it is a service availability advertisement message or a service unavailability advertisement message).
  • delivery message extractor 141 when it does not refer to message DB 120 will first be described below.
  • delivery message extractor 141 When delivery message extractor 141 is instructed by message delivery unit 150 , delivery message extractor 141 immediately instructs delivery message generator 160 to generate a message, and transfers the message generated by delivery message generator 160 to message delivery unit 150 .
  • a process of generating a message in delivery message generator 160 shown in FIG. 7 will be described below with reference to FIG. 8 .
  • node connection monitoring unit 130 determines whether a node is connected or disconnected. If it is judged that a node is connected, then it is determined in step 12 whether the connected node is a service using node or a service providing node. For example, a search message is delivered from delivery message extractor 141 to the connected node. If a response message returns in response to the search message within a preset time, then the connected node is judged as a service providing node. If a response message does not return in response to the search message within the preset time, then the connected node is judged as a service using node.
  • a search message is delivered from delivery message extractor 141 to the connected node. If a response message returns in response to the search message within a preset time, then the connected node is judged as a service providing node. If a response message does not return in response to the search message within the preset time, then the connected node is judged as a service using node.
  • delivery message generator 160 is instructed in step 14 to generate a service availability advertisement message of the connected node. Instructions sent to delivery message generator 160 include the connected node as a node for which a message is to be generated, and the service availability advertisement message as the type of a message to be generated.
  • delivery message generator 160 is instructed in step 16 to generate a service unavailability advertisement message of a node connected to the domain from which the service using node is disconnected.
  • Instructions sent to delivery message generator 160 include the domain from which the service using node is disconnected as a domain for which a message is to be generated, and the service unavailability advertisement message as the type of a message to be generated.
  • delivery message generator 160 is instructed in step 17 to generate a service unavailability advertisement message of the disconnected node. Instructions sent to delivery message generator 160 include the disconnected node as a node for which a message is to be generated, and the service unavailability advertisement message as the type of a message to be generated.
  • Steps 12 , 15 shown in FIG. 8 can be dispensed with. If steps 12 , 15 are dispensed with, then both steps 13 , 14 are executed when a node is connected, and both steps 16 , 17 are executed when a node is disconnected.
  • advertisement search agent module 102 may not have message DB 120 .
  • delivery message extractor 141 when it refers to message DB 120 will be described below.
  • delivery message extractor 141 instructs delivery message generator 160 to generate a message, it also instructs message DB 120 to store the generated message.
  • Delivery message extractor 141 operates differently in the following two cases (p), (1):
  • node connection monitoring unit 130 determines whether a node is connected or disconnected. If it is judged that a node is connected, then it is determined in step 22 whether the connected node has been connected to any monitoring domain in the past. For example, message DB 120 is referred to and checked to see whether or not it stores a service availability advertisement message or a service unavailability advertisement message of the connected node, for thereby determining whether the connected node has been connected to any monitoring domain in the past.
  • delivery message extractor 141 refers to message DB 120 , extracts a message from message DB 120 , and transfers the extracted message to message delivery unit 150 in step 23 in the same manner as delivery message extractor 140 according to the first embodiment.
  • step 22 If it is judged in step 22 that the connected node has not been connected to any monitoring domain in the past, then it is judged in step 24 whether the connected node is a service using node or a service providing node.
  • step 24 is executed.
  • delivery message extractor 141 instructs delivery message generator 160 in step 25 to generate a message for the connected node and transfer the generated message to message delivery unit 150 .
  • delivery message generator 160 is instructed to generated a message, it is also instructed to store the generated message into message DB 120 . Therefore, it is guaranteed at all times that message DB 120 holds both a service availability advertisement message and a service unavailability advertisement message of all service providing nodes connected to any monitoring domain immediately before the node is connected or disconnected.
  • step 23 is executed.
  • steps 22 , 24 may be dispensed with. If only step 22 is dispensed with, then steps 24 , 25 are executed at all times. If only step 24 is dispensed with, then step 25 is executed at all times if the connected node is a new node in step 22 . If both steps 22 , 24 are dispensed with, then step 25 is executed at all times if a node is connected.
  • a process of extracting a message in delivery message extractor 141 in the case (q) will be described below with reference to FIG. 10 .
  • delivery message extractor 141 holds a record of domains and nodes for which delivery message extractor 141 has instructed delivery message generator 160 to generate messages.
  • step 31 node connection monitoring unit 130 determines whether a node is connected or disconnected. If it is judged that a node is connected, then it is determined in step 32 whether the connected node is a service using node or a service providing node.
  • step 33 it is determined in step 33 whether or not delivery message extractor 141 has already instructed delivery message generator 160 to generate a message for the domain to which the node is connected.
  • delivery message extractor 141 refers to message DB 120 , extracts a message from message DB 120 , and transfers the extracted message to message delivery unit 150 in step 34 in the same manner as delivery message extractor 140 according to the first embodiment.
  • delivery message extractor 141 instructs delivery message generator 160 to generate a service availability advertisement message of a node already connected to the domain to which the node is connected in step 35 .
  • Instructions sent to delivery message generator 160 include the domain to which the node is connected as a domain for which a message is to be generated, and the service availability advertisement message as the type of a message to be generated.
  • step 32 If it is judged in step 32 that a service providing node is connected, then it is determined in step 36 whether or not delivery message extractor 141 has already instructed delivery message generator 160 to generate a message for the connected service providing node.
  • step 34 is executed.
  • delivery message extractor 141 instructs delivery message generator 160 to generate a service availability advertisement message of the connected node.
  • Instructions sent to delivery message generator 160 include the connected node for which a message is to be generated, and the service availability advertisement message as the type of a message to be generated.
  • step 38 If it is judged in step 31 that a node is disconnected, then it is determined in step 38 whether the disconnected node is a service using node or a service providing node.
  • step 39 it is determined in step 39 whether or not delivery message extractor 141 has already instructed delivery message generator 160 to generate a message for the domain from which the node is disconnected.
  • step 34 is executed.
  • delivery message extractor 141 instructs delivery message generator 160 to generate a service unavailability advertisement message of a node already connected to the domain from which the node is disconnected in step 40 .
  • Instructions sent to delivery message generator 160 include the domain from which the node is disconnected as a domain for which a message is to be generated, and the service unavailability advertisement message as the type of a message to be generated.
  • step 41 it is determined in step 41 whether or not delivery message extractor 141 has already instructed delivery message generator 160 to generate a message for the disconnected service providing node.
  • step 34 is executed.
  • delivery message extractor 141 instructs delivery message generator 160 to generate a service unavailability advertisement message of the disconnected node.
  • Instructions sent to delivery message generator 160 include the disconnected node for which a message is to be generated, and the service unavailability advertisement message as the type of a message to be generated.
  • Steps 32 , 38 can be dispensed with. If steps 32 , 38 are dispensed with, then both step 33 and the following steps and step 34 and the following steps are executed when a node is connected, and both step 39 and the following steps and step 41 and the following steps are executed when a node is disconnected.
  • delivery message generator 160 When delivery message generator 160 is instructed to generate a message by delivery message extractor 141 , delivery message generator 160 generate a message based on the instructions. When delivery message generator 160 is also instructed to store a message, delivery message generator 160 stores the generated message into message DB 120 .
  • message DB 120 may not exist in the same node as the other components (advertisement search message acquisition unit 110 , node connection monitoring unit 130 , delivery message extractor 141 , delivery message generator 160 , and message delivery unit 150 ) of advertisement search agent module 102 . Rather, single message DB 120 may be incorporated in a database server or the like, and may be shared by a plurality of advertisement search message acquisition units 110 , node connection monitoring units 130 , delivery message extractors 141 , delivery message generators 160 , and message delivery units 150 , so that advertisement search agent module 102 can refer to messages generated by delivery message generators 160 of other advertisement search agent modules 102 .
  • Delivery message generator 160 has an application protocol stack installed for at least detecting a service, of an application run on service using nodes and service providing nodes connected to monitoring domains, or in other words, a function installed to generate and deliver a search message for detecting a service and to interpret application-level contents of a response message in response the search message.
  • Delivery message generator 160 also has a function to generate and deliver a search message for detecting a service with the application protocol stack when delivery message generator 160 is instructed to generate a message, to interpret application-level contents of a response message in response the search message, and to generate a service availability advertisement message and a service unavailability advertisement message from the interpreted contents.
  • Delivery message generator 160 operates differently when a domain is specified for which a message is to be generated and when a node is specified for which a message is to be generated.
  • delivery message generator 160 If a domain is specified for which a message is to be generated, then delivery message generator 160 generates a search message for detecting a service itself, and broadcasts or multicasts the generated search message to the specified domain.
  • Delivery message generator 160 generates a service availability advertisement message and a service unavailability advertisement message of all service providing nodes that are connected to the domain for which a message is to be generated at the time delivery message generator 160 is instructed to generate a message.
  • delivery message generator 160 If a node is specified for which a message is to be generated, then delivery message generator 160 generates a search message for detecting a service itself, and unicasts the generated search message to the specified node.
  • Operation of message delivery unit 150 also differs depending on whether a message generated by delivery message generator 160 is to be delivered to a domain or a node.
  • message delivery unit 150 has a domain delivery function to deliver a message to a domain and a node delivery function to deliver a message to a node. If a message generated by delivery message generator 160 is to be delivered to a domain, the domain delivery function delivers the generated message to the domain. If a message generated by delivery message generator 160 is to be delivered to a node, the node delivery function delivers the generated message to the node. For delivering a message to a node using the node delivery function, the message is converted into a unicast message and the unicast message is delivered to the node.
  • Advertisement search agent module 102 offers the following advantages:
  • Advertisement search agent module 102 has delivery message generator 160 for generating a service availability advertisement message and a service unavailability advertisement message of service providing nodes connected to monitoring domains.
  • advertisement search agent module 102 delivers a message required for a node in a domain and the connected or disconnected node to immediately detect a change in an available service caused by the connection or disconnection of the node.
  • a search message, a service availability message, or a service unavailability message of a node that has been connected to a monitoring domain, a node that is connected to a domain, or a node that is disconnected from a domain has not been acquired in advance, the node that has been connected to the monitoring domain, the node that is connected to the domain, or the node that is disconnected from the domain can detect a change in an available service immediately after the connection or the disconnection has occurred.
  • a change in an available service of a node is detected at all times when a service availability advertisement message or a service unavailability advertisement message transmitted from advertisement search agent module 102 is received by each node.
  • a change in an available service is not detected when a response message in response to a search message not transmitted from each node itself, i.e., a search message transmitted from advertisement search agent module 102 , is received by each node.
  • an application on a service using node is installed in a manner to be able to receive a response message only for a preset time after the application has transmitted a search message, the service using node can detect a change in an available service immediately after the node is connected or disconnected.
  • advertisement search agent module 100 has node connection monitoring unit 130 for detecting the connection and disconnection of a service providing node and a service using node to and from a monitoring domain, and recognizing the connected or disconnected domain and the node identifier of the connected or disconnected node, delivery message extractor 140 for extracting at least one of a message broadcast or multicast in the past by the node and a message broadcast or multicast in the past by another node connected to the domain to or from which the node is connected or disconnected, based on the node identifier and the domain to or from which the node is connected or disconnected which are detected by node connection monitoring unit 130 , and message delivery unit 150 for broadcasting or multicasting the message extracted by delivery message extractor 140 to the domain to or from which the node is connected or disconnected if the message extracted by delivery message extractor 140 is a message transmitted by the connected or disconnected node, and transmitting the message extracted by delivery message extractor 140 to the connected or disconnected node if the message extracted by delivery message extractor 140
  • node connection monitoring unit 130 detects the connection and recognizes the node identifier of the service providing node and the domain to which the node is connected.
  • Delivery message extractor 140 extracts at least one of (A) a service availability advertisement message broadcast or multicast in the past by the service providing node and (B) a search message broadcast or multicast in the past by another node connected to the domain to which the node is connected. If the message extracted by delivery message extractor 140 is the message (A), then message delivery unit 150 broadcasts or multicasts the extracted message to the domain to which the service providing node is connected. If the message extracted by delivery message extractor 140 is the message (B), then message delivery unit 150 broadcasts or multicasts the extracted message to the service providing node.
  • the newly connected service using node when a service using node is newly connected to a domain, the newly connected service using node is able to discover only a service providing node connected to the domain, and when a service providing node is newly connected to a domain, only a service using node connected to the domain is able to discover the service provided by the newly connected service providing node.
  • delivery message extractor 140 and message delivery unit 150 either (i) extracts only a message of a node connected to a domain to or from which the node is connected or disconnected, and delivers the extracted message only to the connected or disconnected node, or (ii) extracts only a message of the connected or disconnected node, and delivers the extracted message to the domain to or from which the node is connected or disconnected. Therefore, the message of the domain to or from which the node is connected or disconnected is prevented from being delivered to nodes unrelated to the domain, and the message of the connected or disconnected node is prevented from being delivered to nodes unrelated to the domain to or from which the node is connected or disconnected.
  • the disconnected node when a node is disconnected from a domain, if the disconnected node is a service providing node, then a service using node connected to the domain from which the node is disconnected is immediately able to recognize that the service provided by the disconnected node has become unavailable. If the disconnected node is a service using node, then the disconnected node is immediately able to recognize the service provided by the domain from which the node is disconnected.
  • delivery message extractor 140 extracts a service unavailability advertisement message delivered in the monitoring domain in the past by the disconnected node or a service unavailability advertisement message delivered in the monitoring domain in the past by a node connected to the domain from which the node is disconnected.
  • Message delivery unit 150 broadcasts or multicasts the extracted message to the domain from which the node is disconnected, or transmits the extracted message to the disconnected node.
  • the node that has been connected to a monitoring domain can detect a change in an available service immediately after the connection or the disconnection has occurred.
  • advertisement search agent module 102 has delivery message generator 160 for generating a service availability advertisement message and a service unavailability advertisement message of a service providing node connected to a monitoring domain.
  • advertisement search agent module 102 delivers a message for a node in a domain and the connected or disconnected node to immediately detect a change in an available service caused by the connection or disconnection of the node.
  • the reason for the fifth advantage is that a node detects a change in an available service at all times by receiving a service availability advertisement message or a service unavailability advertisement message transmitted from advertisement search agent module 102 , and does not detect a change in an available service by receiving a response message in response to a search message (a search message transmitted by advertisement search agent module 102 ) which has not been transmitted by the node itself.

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110274035A1 (en) * 2010-05-04 2011-11-10 Cisco Technology, Inc. Routing to the Access Layer to Support Mobility of Internet Protocol Devices

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8964741B2 (en) * 2011-06-21 2015-02-24 Cisco Technology, Inc. Adjacency discovery through multicast and single-hop messaging
US9578626B2 (en) * 2013-03-15 2017-02-21 Qualcomm Incorporated Systems and methods for sharing context information in a neighbor aware network
WO2016175872A1 (en) * 2015-04-29 2016-11-03 Hewlett Packard Enterprise Development Lp Network based service discovery via unicast messages

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040133640A1 (en) * 2002-10-31 2004-07-08 Yeager William J. Presence detection using mobile agents in peer-to-peer networks
JP2005123686A (ja) 2003-10-14 2005-05-12 Nippon Telegr & Teleph Corp <Ntt> シームレスデバイス制御方法とそのシステム、ゲートウェイ装置、端末及びドメインコントローラ装置
US20050114482A1 (en) 2003-11-20 2005-05-26 Samsung Electronics Co., Ltd. Apparatus and method for requesting service provided by network equipment
JP2005136718A (ja) 2003-10-30 2005-05-26 Canon Inc ネットワークアクセス管理方法、ネットワークアクセス管理装置、ネットワークサービス提供方法、ネットワークサービス提供システム、プログラム及び記憶媒体
US20050185658A1 (en) 2004-02-25 2005-08-25 Fujitsu Limited Gateway apparatus connected to a plurality of networks forming respective different network segments, and program and method for transferring IP packets
JP2005311733A (ja) 2004-04-22 2005-11-04 Olympus Corp 画像補正装置、画像補正方法、及びプログラム
US20060187858A1 (en) * 2004-11-05 2006-08-24 Taniuchi Kenichi Network discovery mechanisms

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3842768B2 (ja) * 2003-08-26 2006-11-08 株式会社東芝 サービス検索装置およびサービス検索方法
JP4334424B2 (ja) * 2004-07-09 2009-09-30 富士通株式会社 ネットワークのリソース，サービス発見方法及び中継ノード装置

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040133640A1 (en) * 2002-10-31 2004-07-08 Yeager William J. Presence detection using mobile agents in peer-to-peer networks
JP2005123686A (ja) 2003-10-14 2005-05-12 Nippon Telegr & Teleph Corp <Ntt> シームレスデバイス制御方法とそのシステム、ゲートウェイ装置、端末及びドメインコントローラ装置
JP2005136718A (ja) 2003-10-30 2005-05-26 Canon Inc ネットワークアクセス管理方法、ネットワークアクセス管理装置、ネットワークサービス提供方法、ネットワークサービス提供システム、プログラム及び記憶媒体
US20050114482A1 (en) 2003-11-20 2005-05-26 Samsung Electronics Co., Ltd. Apparatus and method for requesting service provided by network equipment
JP2005158017A (ja) 2003-11-20 2005-06-16 Samsung Electronics Co Ltd ネットワーク機器により提供されるサービス要請装置及び方法
US20050185658A1 (en) 2004-02-25 2005-08-25 Fujitsu Limited Gateway apparatus connected to a plurality of networks forming respective different network segments, and program and method for transferring IP packets
JP2005244408A (ja) 2004-02-25 2005-09-08 Fujitsu Ltd ネットワーク・セグメントが互いに異なる複数のネットワークに接続されたゲートウェイ装置、およびｉｐパケットを転送するためのプログラムおよび方法
JP2005311733A (ja) 2004-04-22 2005-11-04 Olympus Corp 画像補正装置、画像補正方法、及びプログラム
US20060187858A1 (en) * 2004-11-05 2006-08-24 Taniuchi Kenichi Network discovery mechanisms

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110274035A1 (en) * 2010-05-04 2011-11-10 Cisco Technology, Inc. Routing to the Access Layer to Support Mobility of Internet Protocol Devices
US8520595B2 (en) * 2010-05-04 2013-08-27 Cisco Technology, Inc. Routing to the access layer to support mobility of internet protocol devices

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